In order to detect and determine color of light from a light source, color filters are used to separate out components of light. The resulting intensity of each component is detected in order to determine light color.
For example, when trying to match color using the Commission Internationale de l'Eclairage (CIE) 1931 color matching function (CMF), a light sensor with a red color filter, a light sensor with a green color filter and a light sensor with a blue color filter are used to detect red, green and blue components of light. A transfer function is used to convert the detected red, green and blue components to X, Y and Z tristimulus values used by the CIE 1931 CMF. One disadvantage of this system is that filters are expensive and degrade over time. Additionally, because filters do not exactly correspond with X, Y and Z tristimulus values used by the CIE 1931 CMF, it is necessary to use an intermediate color space and a transfer function to convert detected color components to X, Y and Z values.